Nozzle cap for sealing nozzle particularly used to charge with high pressurized fluid

ABSTRACT

A nozzle cap is disclosed which is threadedly engaged with a distal end of a nozzle through which a compressed fluid is passed. The nozzle cap includes a terminal wall opposed to a distal end face of the nozzle axially with respect to the nozzle, a sealing member placed on the terminal wall so as to adhere closely to the distal end of the nozzle thereby to seal an opening of the nozzle, and a holding wall pressing and holding an edge of the sealing member in co-operation with the terminal wall between the walls.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] This invention relates generally to a nozzle cap threadedlyengaged with a distal end of a nozzle, and more particularly to such anozzle cap threadedly engaged with a nozzle which is used to charge anair conditioner with a refrigerant.

[0003] 2. Description of the Related Art

[0004] Conventional nozzle caps comprise a thread adapted to bethreadedly engaged with a distal end of a nozzle and a terminal wallprovided at a proximal end side of the thread so that the distal end ofthe nozzle is butted against the proximal end. A sealing member providedon the terminal wall is closely adhered to the distal end of the nozzleso that the nozzle cap seals an opening of the nozzle. Such a sealingmember is shown by reference numeral 12 in JP-A-2001-287521 or byreference numeral 24 in JP-A-5-312439.

[0005] In the above-described nozzle cap, the sealing member is merelyplaced on the terminal wall or simply engaged with the thread.Accordingly, there is a possibility that the sealing member may separatefrom the body of the nozzle cap. The assignee of the present applicationexamined the cause for separation of the sealing member and found thatthe sealing member, when pressed against the nozzle, adhered to thenozzle. When the nozzle cap is disengaged from the nozzle, the sealingmember separates from the thread of the cap to remain at the nozzleside. Particularly in the nozzle cap used for a nozzle through which ahigh-pressurized fluid such as an air conditioner refrigerant, thesealing member is subjected to a large inner pressure to be pressedagainst the nozzle, thereby adhered to the nozzle. Thus, the sealingmember cannot be prevented from separation in the conventional nozzlecaps.

SUMMARY OF THE INVENTION

[0006] Therefore, an object of the present invention is to provide anozzle cap which can prevent the sealing member from separationtherefrom.

[0007] The present invention provides a nozzle cap threadedly engagedwith a distal end of a nozzle through which a compressed fluid iscapable of passing. The nozzle cap comprises a terminal wall opposed toa distal end face of the nozzle axially with respect to the nozzle, asealing member placed on the terminal wall so as to adhere closely tothe distal end of the nozzle thereby to seal an opening of the nozzle,and a holding wall pressing and holding an edge of the sealing member inco-operation with the terminal wall therebetween.

[0008] In the foregoing nozzle cap, the edge of the sealing member ispressed between the terminal wall and the holding wall to be heldtherebetween. Consequently, the sealing member can be prevented fromremoval from the nozzle cap even when adherent to the nozzle upondisengagement of the nozzle cap from the nozzle.

[0009] In a preferred form, at least one of the terminal wall and theholding wall or a portion of the holding wall opposed to the protrudingwall is provided with an engagement projection biting into the sealingmember. Since the locking protrusion penetrates the sealing member, thesealing member can be prevented from dropping out of the space betweenthe terminal and holding walls.

[0010] In another preferred form, the holding wall is disposed at aposition where the distal end face of the nozzle is butted against theholding wall. When the distal end face of the nozzle is butted againstthe holding wall, the holding wall can be prevented from deforming insuch a direction that the holding member departs from the sealingmember. Consequently, the sealing member can reliably be held betweenthe terminal and holding walls.

[0011] In further another preferred form, the nozzle cap furthercomprises a generally cylindrical cover fitted with an outer peripheryof the cap so as to surround the sealing member. In this construction,the cylindrical cover can be fitted with the cap after attachment of thesealing member. Consequently, the sealing member can be attached easily.Furthermore, the sealing member can be protected by the cylindricalcover.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Other objects, features and advantages of the invention willbecome clear upon reviewing the following description of embodiments,made with reference to the accompanying drawings, in which:

[0013]FIG. 1 is a side section of a nozzle and a nozzle cap inaccordance with one embodiment of the present invention;

[0014]FIG. 2 is a side section of the nozzle and nozzle cap attached tothe nozzle;

[0015]FIG. 3 is a partially enlarged section of the nozzle cap;

[0016]FIG. 4 is a plan view of the nozzle cap;

[0017]FIG. 5 is a side section of the nozzle cap in accordance with asecond embodiment of the present invention;

[0018]FIG. 6 is a partially enlarged section of the nozzle cap of onemodified form; and

[0019]FIG. 7 is a partially enlarged section of the nozzle cap ofanother modified form.

DETAILED DESCRIPTION OF THE INVENTION

[0020] An embodiment of the present invention will be described withreference to FIGS. 1 to 4. In the embodiment, a nozzle cap 10 isattached to a nozzle 50 through which a car air-conditioner is chargedwith a refrigerant serving as a compressed fluid. The nozzle 50 has aproximal end provided with a male thread 51. The male thread 51 isthreadedly engaged with a suitable component of the car air-conditioner,whereby a flow passage 52 inside the nozzle 50 communicates with arefrigerant passage 66 provided in the component of the carair-conditioner.

[0021] A valve core 53 is provided in the middle of the flow passage 52of the nozzle 50. The valve core 53 includes a valve core body 54, amoving shaft 55 extending through the valve core body and a valveelement 56 provided on one end of the moving shaft. A coil spring 57 isprovided between the valve core body 54 and the moving shaft 55. Thecoil spring 57 usually biases the valve element 56 so that the flowpassage 52 is closed by the valve element. Furthermore, the valveelement 56 is also biased by a pressure applied from the refrigerantpassage 66 into a closing state. In a case where the refrigerant ischarged or supplied from the distal end side of the nozzle 50, the valvecore 53 is opened when a charge pressure is larger than a sum of aninternal pressure of the refrigerant passage 66 and a spring force ofthe coil spring 57, whereupon the refrigerant is supplied from thenozzle 5 into the refrigerant passage 66.

[0022] A distal end opening of the nozzle 50 has an inner edge formedwith a tapered face 58 whose diameter is gradually increased toward thedistal end. The distal end opening of the nozzle 50 further has an outeredge formed with a tapered face 59 whose diameter is gradually reducedtoward the distal end. The tapered face 59 has a smaller inclinationthan the tapered face 58. The distal end of the nozzle 50 includes adistal end face 61 which is located between the tapered faces 58 and 59and which is perpendicular to the axis of the nozzle. The distal end ofthe nozzle 50 has a female thread 60 formed inner than the tapered face58. A nozzle cap 10 in accordance with the present invention isthreadedly engaged with the female thread 60.

[0023] The nozzle cap 10 comprises a cap body 11, a sealing member 12and a cylindrical cover 13. The cap body 11 is generally tapered towardthe nozzle 50 and has a distal cylindrical portion 14 having a malethread 15 formed in an outer circumferential face thereof. The malethread 15 extends from an axially middle portion of the cylindricalportion 14 to the distal end. The cylindrical portion 14 includes aportion located between the male thread 15 and the proximal end thereof.The portion serves as a seal-fitting portion 16 having a diametersmaller than a root diameter of the male thread 15.

[0024] The cap body 11 includes a portion located between thecylindrical portion 14 and the proximal end. The portion serves as aterminal wall 17 having a larger diameter than the cylindrical portion14. The terminal wall 17 has an end face axially opposed to the distalend face 61 of the nozzle 50. A protruding wall 18 protrudes from anouter edge of the end face of the terminal wall 17 toward the nozzle 50.Before the sealing member 12 is fitted with the cap body 11, theprotruding wall 18 has a cylindrical shape and extends straightforwardalthough this is not shown. A distal end of the protruding wall 18 iscrimped so as to be pushed down inside the sealing member 12 while thesealing member is placed on the end face of the terminal wall 17.Consequently, a holding wall 19 is formed which presses the outer edgeof the sealing member 12 against the terminal wall 17 and holds theouter edge between the terminal wall and itself.

[0025] A locking protrusion 20 is formed on a portion of the terminalwall 17 opposed to the inner edge of the holding wall 19 as shown inFIG. 3. The locking protrusion 20 is tapered toward the terminal wall17. The locking protrusion 20 is continuously formed over the entireperiphery of the terminal wall 17. When the holding wall 19 is thenpressed against the sealing member 12, the locking protrusion 20penetrates the sealing member and is held in the penetrating state.

[0026] The sealing member 12 is formed into an annular shape and fittedwith a portion of the cap body 11 between the seal-fitting portion 16and the protruding wall 18. The sealing member 12 has an inner edgeformed with a adhering protrusion 30 and an outer edge formed with aflat portion held between the terminal wall 17 and the protruding wall18. A distal end of the adhering protrusion 30 has a semicircularsection before the nozzle cap 10 is attached to the nozzle 50, as shownin FIGS. 1 and 3.

[0027] The cap body 11 has an end which is spaced away from the malethread 15 and is formed with an operating portion 21 extending sidewaysfrom the terminal wall 17. The operating portion 21 generally has theshape of a hexagon with chamfered vertexes as shown in FIG. 4, forexample. A character mark “H” indicative of a high pressure line isprinted on a central end face of the operating portion 21. The mark isdesignated by reference numeral “22.”

[0028] The outer periphery of the cap body 11 includes a part risingfrom the operating portion 21. One end of the cylindrical cover 13 isfitted with the rising part. More specifically, the cylindrical cover 13is made of a semitransparent synthetic resin. The end of the cylindricalcover 13 is formed with a first locking portion 23 which has an innercircumferential face inclined toward the center thereof or has athickness gradually increased as the locking portion extends toward theother end of the cover. On the other hand, the cap body 11 includes asecond locking portion 24 formed at the proximal end side of theprotruding wall 18. The second locking portion 24 has an outercircumferential face inclined outward or has a diameter graduallyincreased as it gets near the operating portion 21. The cap body 11 ispushed inside the cylindrical cover 13 after the distal end of theprotruding wall 18 has been crimped thereby to be formed into theholding wall 19. The cylindrical cover 13 is deformed such that it isspread, whereupon the first locking portion 23 of the cover 13 ispositioned between the operating portion 21 and the second lockingportion 24. As a result, the cylindrical cover 13 is prevented fromfalling off by the engagement of both locking portions 23 and 24 whilethe distal end of the cover is butted against the operating portion 21so as to be fixed to the cap body 11.

[0029] The above-described nozzle cap operates as follows. A flowpassage 52 of the nozzle 50 is closed by a valve core 53 of the nozzlewhen the car air conditioner has been charged with the refrigerant.However, since there is a possibility that the refrigerant may leak fromthe nozzle 50, the nozzle cap 10 needs to be attached to the distal endof the nozzle 50.

[0030] In order that the nozzle cap 10 may be attached to the nozzle 50,the male thread 15 of the nozzle cap 10 is threadedly engaged with thefemale thread 60 of the nozzle 50. The cylindrical cover 13 is made ofthe semitransparent resin as described above. Accordingly, the distalend of the nozzle 50 can be viewed through the cover 13. The nozzle cap10 is threadedly engaged with the nozzle 50 until the holding wall 19 ofthe nozzle cap 10 is abutted against or is adjacent to the distal end 61of the nozzle 50. The adhering protrusion 30 is pressed against thetapered face 58 thereby to adhere closely to the latter, and the innernarrow portion of the tapered face is also pushed inward such that theadhering protrusion 30 also adheres to the seal-fitting portion 16 ofthe cap body 11. At this time, the holding wall is prevented fromdeforming in such a direction that it departs from the sealing member 12since the holding wall 19 of the nozzle cap 10 is butted against thedistal end 61 of the nozzle 50. Consequently, the sealing member 12 isreliably held between the terminal wall 17 and the holding wall 19.Furthermore, the sealing member 12 is restrained from spreading so as toescape outward. Consequently, a higher sealing performance can beachieved from the foregoing nozzle cap 10 than from the conventionalnozzle cap.

[0031] The nozzle cap 10 is turned in the opposed direction as that inthe attachment when to be detached from the nozzle 50. In this case, thesealing member 12 is subjected to a rotational force when closelyadherent to the nozzle 50. However, since the sealing member 12 ispressed and held between the terminal wall 17 and the holding wall 19,the sealing member is turned together with the cap body 11 thereby to bereleased from the adherence to the nozzle 50. Even if the sealing member12 should be turned between the walls 17 and 19 while being adherent tothe nozzle 50, the sealing member would be separated from the taperedface 58 of the nozzle 50 while being held at the cap body 11 sidebetween the walls 17 and 19 and by the engagement of the lockingprotrusion 20 upon axial movement in such a direction as to depart fromthe nozzle.

[0032] As described above, the nozzle cap 10 of the embodiment isprovided with the holding wall 19 cooperating with the terminal wall 17to press and hold the edge of the sealing member 12. Furthermore, theterminal wall 17 includes the locking protrusion 20 penetrating into thesealing member 12. Accordingly, the sealing member 12 adherent to thenozzle 50 is prevented from being separated from the nozzle cap 10 whenthe nozzle cap is detached from the nozzle. Furthermore, the distal endof the protruding wall 18 is crimped to be formed into the holding wall19 after the sealing member 12 has been assembled to the nozzle cap 10,and thereafter, the cylindrical cover 13 is fitted with the nozzle cap.Thus, the sealing member 12 can easily be assembled to the nozzle cap 10and the protruding wall 18 can easily be crimped. Additionally, thesealing member 12 can be surrounded by the cylindrical cover 13 therebyto be protected.

[0033] The nozzle cap 10 is fitted with the inner circumferential wallof the nozzle 50 in the foregoing embodiment. In a second embodiment,however, the nozzle cap 70 is fitted with an outer circumferential wallof the nozzle 67 as shown in FIG. 5. Only the differences of the secondembodiment from the first embodiment will be described with reference toFIG. 5.

[0034] The nozzle 70 of the second embodiment includes a cylindricalmember 71 with one of two ends closed a terminal wall 72. The innercircumferential wall of the cylindrical member 71 is formed with afemale thread 79 which is threadedly engaged with the male thread 68formed on the outer circumferential face of the nozzle 67.

[0035] The terminal wall 72 includes an inner face 72A located insidethe cylindrical member 71. The sealing member 73 is provided on theinner face 72A of the terminal wall 72. The sealing member 73 has agenerally annular shape and includes the axially protruding adheringprotrusion 74 formed along the outer circumferential edge thereof. Thesealing member 73 further includes the axially flat portion 75 formedalong an inner circumferential edge thereof. The terminal wall 72includes a protruding wall 76 rising from portion of the terminal wall72 located inside the sealing member 73. The distal end of theprotruding wall 76 is crimped thereby to be pressed down toward the flatportion 75 of the sealing member 73, whereby the holding wall 77 isformed. The terminal wall 72 includes a part along which the sealingmember 73 is provided. The part of the terminal wall 72 is formed withthe locking protrusion 78 protruding toward the sealing member 73. Thelocking protrusion 78 penetrates into the sealing member 73 when theholding wall 77 is pressed against the sealing member.

[0036] When the nozzle cap 70 is threadedly engaged with the nozzle 67thereby to be attached to the latter, the tapered face 69 formed on theouter edge of the distal end of the nozzle 67 adheres closely to theadhering protrusion 74 of the sealing member 73, and the distal end 67Aof the nozzle 67 is butted against the holding wall 77. The nozzle cap70 of the second embodiment constructed as described above operates inthe same manner as described above in the first embodiment and achievesthe same effect as that in the first embodiment.

[0037] Modified forms of the invention will now be described. Thelocking protrusions 20 and 78 are formed along the overallcircumferences of the terminal walls 17 and 72 in the foregoingembodiments respectively. However, the locking protrusion may be formeddiscontinuously along the circumference of the terminal wall, instead.

[0038] The locking protrusions 20 and 78 are formed on the terminalwalls 17 and 72 in the foregoing embodiments respectively. However, thelocking protrusion may be formed on the holding wall or the lockingprotrusions may be formed on the terminal wall and the holding wallrespectively, instead.

[0039] A locking protrusion 80 may be formed on the seal-fitting portion16 in the first embodiment as shown in FIG. 6. Furthermore, the nozzlecap may include both the locking protrusion 20 formed on the terminalwall 17 and the locking protrusion 80 formed on the seal-fitting portion16. Additionally, the protruding walls 18 and 76 are cylindrical in theforegoing embodiments respectively. However, the protruding wall may beformed circumferentially discontinuously, instead.

[0040] The cylindrical cover 13 is made of the synthetic resin in thefirst embodiment. However, the cylindrical cover may be formed ofanother material, instead. Furthermore, the nozzle cap 10 is attached tothe nozzle 50 including the built-in valve core 53 in the firstembodiment. However, the invention may be applied to a nozzle cap whichis attached to a distal end of a cylindrical nozzle with no valve core,instead.

[0041] In the foregoing embodiments, the sealing members 12 and 73 arefitted with the terminal walls 17 and 72, and thereafter, the distalends of the protruding walls 18 and 76 are crimped thereby to be bentinto the holding walls 19 and 77, respectively. However, the holdingwall 19 or 77 may previously be formed on the terminal wall 17 or 72,and the edge of the sealing member 12 or 73 may be pushed into the spacebetween the terminal wall and the holding wall, instead. Furthermore,the holding wall 19 or 77 may previously be formed on the terminal wall17 or 72, and the sealing member may be formed by pouring molten rubberor resin into the space between the terminal and holding walls, instead.

[0042] The foregoing description and drawings are merely illustrative ofthe principles of the present invention and are not to be construed in alimiting sense. Various changes and modifications will become apparentto those of ordinary skill in the art. All such changes andmodifications are seen to fall within the scope of the invention asdefined by the appended claims.

What is claimed is:
 1. A nozzle cap threadedly engaged with a distal endof a nozzle through which a compressed fluid is capable of passing, thenozzle cap comprising: a terminal wall opposed to a distal end face ofthe nozzle axially with respect to the nozzle; a sealing member placedon the terminal wall so as to adhere closely to the distal end of thenozzle thereby to seal an opening of the nozzle; and a holding wallpressing and holding an edge of the sealing member in co-operation withthe terminal wall therebetween.
 2. A nozzle cap according to claim 1,wherein the holding wall comprises a protruding wall protruding from theterminal wall and bent to the sealing member side.
 3. A nozzle capaccording to claim 2, wherein at least one of the terminal wall and theholding wall or a portion of the holding wall opposed to the protrudingwall is provided with an engagement protrusion biting into the sealingmember.
 4. A nozzle cap according to claim 1, wherein the holding wallis disposed at a position where the distal end face of the nozzle isbutted against the holding wall.
 5. A nozzle cap according to claim 2,wherein the holding wall is disposed at a position where the distal endface of the nozzle is butted against the holding wall.
 6. A nozzle capaccording to claim 3, wherein the holding wall is disposed at a positionwhere the distal end face of the nozzle is butted against the holdingwall.
 7. A nozzle cap according to claim 1, wherein the nozzle has atapered face formed on the distal end thereof, the sealing memberincludes an adherent protrusion which protrudes toward the tapered faceof the nozzle and a flat portion located inside or outside the adherentprotrusion, and the holding wall and the terminal wall hold the flatportion of the sealing member therebetween.
 8. A nozzle cap according toclaim 2, wherein the nozzle has a tapered face formed on the distal endthereof, the sealing member includes an adherent protrusion whichprotrudes toward the tapered face of the nozzle and a flat portionlocated inside or outside the adherent protrusion, and the holding walland the terminal wall hold the flat portion of the sealing membertherebetween.
 9. A nozzle cap according to claim 3, wherein the nozzlehas a tapered face formed on the distal end thereof, the sealing memberincludes an adherent protrusion which protrudes toward the tapered faceof the nozzle and a flat portion located inside or outside the adherentprotrusion, and the holding wall and the terminal wall hold the flatportion of the sealing member therebetween.
 10. A nozzle cap accordingto claim 4, wherein the nozzle has a tapered face formed on the distalend thereof, the sealing member includes an adherent protrusion whichprotrudes toward the tapered face of the nozzle and a flat portionlocated inside or outside the adherent protrusion, and the holding walland the terminal wall hold the flat portion of the sealing membertherebetween.
 11. A nozzle cap according to claim 8, wherein theprotruding wall is formed into a cylindrical shape and surrounds thesealing member.
 12. A nozzle cap according to claim 9, wherein theprotruding wall is formed into a cylindrical shape and surrounds thesealing member.
 13. A nozzle cap according to claim 7, furthercomprising a generally cylindrical cover fitted with an outer peripheryof the cap so as to surround the sealing member.
 14. A nozzle capaccording to claim 8, further comprising a generally cylindrical coverfitted with an outer periphery of the cap so as to surround the sealingmember.
 15. A nozzle cap according to claim 9, further comprising agenerally cylindrical cover fitted with an outer periphery of the cap soas to surround the sealing member.
 16. A nozzle cap according to claim10, further comprising a generally cylindrical cover fitted with anouter periphery of the cap so as to surround the sealing member.
 17. Anozzle cap according to claim 13, wherein the cylindrical cover is madeof a transparent or semi-transparent synthetic resin.
 18. A nozzle capaccording to claim 14, wherein the cylindrical cover is made of atransparent or semi-transparent synthetic resin.
 19. A nozzle capaccording to claim 15, wherein the cylindrical cover is made of atransparent or semi-transparent synthetic resin.
 20. A nozzle capaccording to claim 16, wherein the cylindrical cover is made of atransparent or semi-transparent synthetic resin.